1. Field of the Invention
The present invention relates to the testing of computing equipment, and more particularly, to a method and system for indicating the status of computer equipment during burn-in testing.
2. Description of the Related Technology
During the manufacture of computers, the manufacturer assembles and interconnects a variety of components, such as a motherboard, a floppy disk drive, a hard disk drive, a video card and a power supply, into a case. At the end of the assembly operations, the manufacturer conducts a series of tests on the finished computers to determine if they are ready to ship to customers. Often, manufacturers include a burn-in test of the finished computer system to improve the reliability of the systems and to reduce the number of "dead on arrival" (DOA) systems received by the customers.
A burn-in test of the finished system eliminates those systems with a high infant mortality. This is because the failure rate of electrical components in a computer system often follows a so-called "bathtub" curve. In the bathtub curve, there are three regions. The first region corresponds to a high failure rate due to infant mortality. The second region corresponds to a low failure rate and includes the useful operating life of an electrical component. Lastly, the third region corresponds to a high failure rate associated with lifetime failures due to wear out and break down of components. Thus, manufacturers use a burn-in test to place systems in the second region, corresponding to the useful life of the computer, where there is a low failure rate.
To perform the burn-in test, a manufacturer often loads a finished computer with various proprietary test and diagnostic software programs to test the system components. The test and diagnostic programs often display test status and results on a display connected to the computer. Thus, during the test, a manufacturing operator must periodically check the display to determine (i) if the test is still in progress or (ii) if the system has passed the test or (iii) if the system has failed the test. For high volume manufacturing operations, large numbers of expensive computer displays are required to perform these tests. Computer manufacturers must incur additional costs for factory floorspace occupied by these expensive computer displays. Moreover, the computer manufacturer may also lose profits on the portion of its otherwise salable displays that are set aside for use in burn-in testing.
To reduce the costs described above, computer manufacturers have used mechanisms other than a computer display to display test results. For example, U.S. Pat. No. 5,353,240, assigned to Dell USA, discloses a boot test apparatus which can temporarily couple to one or more existing ports on the computer, conduct a boot test on the computer and indicate to an operator, using a plurality of light emitting diodes or a cathode ray tube, whether the computer has passed or failed the test. Similarly, the use of a console panel having LEDs to indicate failure of a module in a computer system having one or more CPU modules, an I/O module and one or more memory modules is disclosed in U.S. Pat. No. 5,519,832, assigned to Digital Equipment Corporation. Lastly, U.S. Pat. No. 5,225,816, assigned to Motorola, Inc., discloses an electrical connector having electronics mounted therein to connect an information bus to an electrical component and to provide a visual display indicating the flow of information through the bus. However, these mechanisms for displaying test results can not substitute for a computer display used in burn-in without modifications to the proprietary test and diagnostic software. Similarly, although each of these mechanisms may detect and indicate a failure, they do not capture information related to failure modes and conditions normally displayed on a display. Thus, to improve their profitability and manufacturing efficiency, computer manufacturers require a mechanism that performs the function of the computer displays during testing without their associated costs.